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C. C. HERITAGE INDUGTIVELY HEATED DRYING DRUM Filed Feb. 10, 1927 Feb. 5, 1929. 1,701,156

Patented Feb. 5, 1929.

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CLARK G. HERITAGE, OF CORNELL, WISCONSIN.

INDUCTIVELY-HEATED DRYING DRUM.

Application filed February 10, 1827.

This invention relates to an inductively heated drying drum and while devices embodying the present invention are capable of a wide held of application, the apparatus herein described is particularly adapted for the drying of paper, paper board and the ihe.

Drying drums for these and similar purposes have been heretofore quite generally heated by steam introduced into the interior thereof. As will be apparent, the steam heating of such apparatus involves many limitinofactors and is dificult to accurately control under all conditions.

It is accordingly an important object of this invention to provide a drying drum or cylinder which is heated by an electric current induced in its shell and which obviates many of the diticulties and disadvantages attendant upon the use of steam as a heating medium.

It is afurther important object of this invention to provide a drier drum having an insulated shell which forms the secondary of an alternating current transformer and which has heatingv currents'induced therein by the action of alternating current flowing in a transformer primary coil inside said shell or drum.

Other and further important objects of this invention will be apparent from the dis closures in the specification and the accompanying drawings.

The invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings:

Figure 1 is a central vertical section taken through a drier drum embodying the principles of this invention with parts shown in elevation.

Figure 2 is a section on the line IIII of Figure 1.

Figure 3 is an enlarged detail section illustrating a method of mounting the primary windings.

As shown on the drawings:

The reference numeral 1 designates drum end pieces which are preferably of metallic construction and which act to support a metallic cylinder 2 in such a manner as to provide a cylindrical drum similar in external appearance to usual type drums. Elie mo tallic cylinder 2 is electrically insulated from Serial No. 167,157.

the end pieces 1 by rings 3 of insulating material which are plainly shown in Figure 1. In order that the drum afiorded by the end pieces 1 and the metallic cylinder 2 may be rotatably supported in suitable bearings such. as provided in drier housings or the like, trunnions 4e are secured to the end pieces 1 in any desired manner. These trunnions 4: are preferably hollow for the purpose to be described hereinafter.

Supported inside the drum afforded by the and pieces i and the metallic cylinder 2 is :1 spider or frameu-orl; which I have designated in general l the reference numeral Said spit er or framework 5 may be con.- veniently su iported on brackets 6 secured to the insides of the end pieces 1 and mounted on longitudinz-il members 5. Forming a part of said ameworlr 5 are a plurality of insulate; blocks '7 which serve to support an electrical conductor 8 of copper wire or other suitable material wound on said framework in the form of a usual helical coil or, if desired, in the form of usual ring coils connected either in series or parallel and suitably controlled. The longitudinal members 5 are preferably separated at any desired number of points intermediate their ends by suitable insulating members 9, a detail of such insulating members being shown in Figure 3. The ends of the coil formed by the conductor 8 may be led outwardly as at 8 through the axial passages in the trunnions l and thence connected to a suitable source of alternating current electrical energy.

It will be apparent from the foregoing construction that when an alternating electric current is passed through the coil afforded by the wound conductor 8 that said current will induce in the single turn secondary afforded by the metallic cylinder or shell 2 an electric current of high amperage and low voltage in accordance with the well lmown principles of transformer operation. This electric current induced in the cylinder or shell 2 will, of course, raise the temperature thereof and it is obvious that the temperature may thus be raised to practically any desired degree required for practical drying purposes.

It i" evident that when the heating of the cylindrical shell 2 is effected in this manner tl the temperature of salt shell may be very accurately controlled, and it is further wiing high pressures. It is further evident that" the device can be designed to operate at a much higher speed of rotation. It is also possible .to make the cylindrical member or shell 2 of lighter material than would be practicable with steam heated driers. Many other advantages Will be obvious to those skilled in the.art.= .=The shell 2 may be opened or closed at its 7 ends as conditions require. The interior of the cylinder primary may also be cooled if deslred by forcing air through the trunnions.-

v It is further obvious that the primary current zarrying element need not be rotatable relative to the sh ell Also, as I have previously indicated herein, the apparatus of-thisinvention is particularly adapted .for use. in connection with dryingof paper, board and the like due to thefact that speedier operation and an economyofrspace may he obviously obtained as Well as a better control of the drying temperatures and consequently, of the moisture content of the'dried product. It 'isalso apoarent that a aratus involviin the urinl p a i ciples -of this .inventionrwill readily lend itself to a variety of other uses.

I am awarethat numerous details of this invention may be varied through a Wide range Without departing from the principles-of this inventiomand I therefore donot purpose lnnnmg. the patent granted, otherwise than.

v necessitated by. the prior art,

I claim asmy invention:

1. A drier, comprising a rotatable cylindrical transformer secondary. element having supporting end members secured thereto secured to the end members, a fraine w'ithin the said secondary element supported by the aforesaid end members, and having a primarytransformer-cod Wound thereon and in- =-sulated therefrom, and current conducting to accomplish the objects of this invention.

means connected to the said primary element extending through the said hollow trunnions.

2. A drier, comprising a rotatable cylindrical transformer secondary element having supporting end members secured thereto and insulated therefrom, hollow trunnions secured to the end-members, a frame Within the said secondary element supported solely by-the aforesaid end members, and having a primary transformer coil Wound thereon and insulated therefrom, and current conducting means connected to the said primary element extending through the hollow trunnions.

'3. A drier, comprising arotatable cylindrical transformer secondary element having supporting end members secured thereto and insulated therefrom, a frame Within the secondary element supported by the said end members having a primary transformer coil Wound thereon and insulated therefrom, hollow trunnions securedto the aforesaid end members, conductor means connected to the said primary coil extending through said trunnions, the said trunnions adapted to function as rotatable supports for the said cylindrical element and to condu -t air to the interior of the drier.

A drier, comprising a rotatable transformer secondary element, supporting members secured to the said secondary member and insulated therefrom, an air-cored pri mary transformer element Within and in spaced relationto the said secondary and mounted on the said supporting members, and conduit-means on the said. supporting members to conduct air to the interior of the saiddrier.

5. A, drier, comprising a rotatable transformer secondary element, supporting members therefor secured to the said secondary element and insulated therefrom, and an air cored primary transformer element Within and 111 spaced relation to thesaid secontiary hand ansulated therefrom,- hollow trunnions 1 County, 'iVisconsin.

CLARK i-GE. 

